9 replies to this topic

[pete l]

Hi all,

 

anyone here got a portable spot welder and knows how to set it up and use it to get good spot welds ?

 

I've got a TELWIN one and I can't get good welds.

 

thanks

 

Pete.

 

[Richc69]

No sorry, but from what I know the metal needs to be clean and close fitting and electrodes aligned. It's then about clamping force and duration unless your spot welder has a power control. Are the electrode tips clean?

[pete l]

Yes clean tips, clean metal too, tight together. 

 

I've been watching youtube and there are some interesting videos that make me think my clamping force is nowhere near hard enough. 

[Richc69]

Is there any adjustment for the clamping force,  and have you tried sharpening the tips to get a smaller contact patch?

[Daz1968]

I have been using a clarke spotwelder with pretty good results, what I would advise is to make sure tips are clean, then set them so the metal to be welded is a tight sliding fit in between them, the adjustment for pressure start at about halfway if you have the short arms and the timer on about half way, material to be welded must be clean and clamped securely together. Do a trial weld, if it burns through increase pressure and try again, repeat until neat weld. Then if you need to increase or decrease timer to get a nice strong weld. You can test it by breaking the joint it should leave a hole on the one piece when broken.

Hope this helps as it's method I used

[pete l]

I couldn't get my head around the bit where if it's blowing through, increase the clamping force. It just didn't seem logical to me. I was releasing the pressure thinking the force was pushing the molten metal out.
It's getting better, will keep trying.
Thanks

[Daz1968]

I have found it blows through when there is a gap between tips and plate, presume it arcs to surface and burns, when Increased pressure the weld was much better. I presume this is due to current flowing from one tip to the other without arcing so metal melts correctly in centre

[pete l]

I think you are spot on there. What you say is exactly what I learned on YouTube videos, resistance welding, some really good explanations there.

Pete.

[Richc69]

More pressure = less resistance so lower heat and less blow through

[Richc69]

I won a single phase miller spot welder with long arms on ebay,  its mounted on a stand with a foot pedal but the seller said it can be removed and used as a portable unit,  I will be picking it up tomorrow if it checks out ok and is as described.  Just got to find space for it in my garage!